<?php
/**
 * PHPExcel
 *
 * Copyright (c) 2006 - 2013 PHPExcel
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PHPExcel
 * @package    PHPExcel_Shared
 * @copyright  Copyright (c) 2006 - 2013 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
 * @version    1.7.9, 2013-06-02
 */


/**
 * PHPExcel_Shared_PasswordHasher
 *
 * @category   PHPExcel
 * @package    PHPExcel_Shared
 * @copyright  Copyright (c) 2006 - 2013 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
class PHPExcel_Shared_PasswordHasher {
	/**
	 * Create a password hash from a given string.
	 *
	 * This method is based on the algorithm provided by
	 * Daniel Rentz of OpenOffice and the PEAR package
	 * Spreadsheet_Excel_Writer by Xavier Noguer <xnoguer@rezebra.com>.
	 *
	 * @param    string $pPassword Password to hash
	 *
	 * @return    string                Hashed password
	 */
	public static function hashPassword($pPassword = '') {
		$password = 0x0000;
		$charPos = 1; // char position

		// split the plain text password in its component characters
		$chars = preg_split('//', $pPassword, -1, PREG_SPLIT_NO_EMPTY);
		foreach ($chars as $char)
		{
			$value = ord($char) << $charPos++; // shifted ASCII value
			$rotated_bits = $value >> 15; // rotated bits beyond bit 15
			$value &= 0x7fff; // first 15 bits
			$password ^= ($value | $rotated_bits);
		}

		$password ^= strlen($pPassword);
		$password ^= 0xCE4B;

		return (strtoupper(dechex($password)));
	}
}
